Modeling of Biofiltration Process for Removal of Vinyl Chloride from an Air Stream by Modified Ottengraf Model

In this paper, the modified Ottengraf model (MOM), as a mathematical model, is applied to modeling the biofiltration process. The model facilitates considering both biological reaction and diffusion limitations simultaneously. The main advantages of this model are simplicity and an analytical solution compared with other mathematical models for biofiltration process. The modeling results show that the modified Ottengraf model can predict the experimental results for vinyl chloride removal from an air stream with an R-squared value higher than 0.95 and the relative errors between the model and the experimental results for first, second, and third column were 0.41, 0.59, and 0.54 respectively. Kinetic parameters such as reaction rate constant were estimated by fitting the measurements to the model for three columns as 1, 1.042, and 0.9957 g/m3.hr respectively. Using fitted parameters, it is possible to predict biofilter performance in other experimental conditions. According to the OSHA standard, for achieving an allowable VC concentration, during 8-hour work shifts in the outlet stream of the biofilter under consideration, the flow rate and empty bed residence time should be 0.129 m3/hr and 196 sec respectively. The removal efficiency of 90% was achieved using the mentioned empty bed residence time and flow rate.